How are Unacceptables and Must-Haves detected/proposed by which algorithm?

Question

Conducting an ACBC investigation, respondents will be asked about unacceptable and must-have features based on choices the Screening Section.

I am interested in how exactly the suggested unacceptable/must-have levels are derived? Which algorithm is used for this?

(I am aware of the design algorithm for creating near-neigbor concepts based on the BYO, but here I would find out about the mechanism behind the identification of must-haves/unacceptables).
Thanks in advance!

Answer 1

We simply look at which levels are included in concepts this respondent marked "a possibility" vs. "not a possibility".   For example, if a respondent never says a "red" concept is "a possibility," then we suspect "red" may be an unacceptable level.  We then ask respondents in a "unacceptable" probing question if indeed "red" is an unacceptable level.  Only if the respondent confirms the rule do we take "red" as unacceptable.